It’s a very disturbing film, german as far as I remember, where the main character is relentlessly obsessed with killing. Shortly after being released from a mental institution, he breaks into a seemingly vacant house, but shortly after, the inhabitants (one of them on a wheel chair) come back, and the carnage begins…

At some point, he painstakingly drags a body throughout a tunnel under the house, towards the car. I also remember that, by the end of the film, he is involved in a car accident which reveals the body of one of his victims in the trunk.

Thank you all for your help !